Nano Alumina or Silica Dispersed in Polystyrene

ABSTRACT

Disclosed is a method of making a polystyrene based nanocomposite by combining a monomer with a nanoparticle to form a mixture and subjecting the mixture to polymerization conditions to produce a polymeric composite. In an embodiment the nanoparticle has been treated with an additive prior to combining with the monomer and the additive contains a silane moiety.

FIELD

Embodiments of the present invention generally relate to polystyrene. Inparticular, embodiments of the invention relate to incorporating alayered compound such as clay nanoplatelets, aluminas and silicas intopolystyrene.

BACKGROUND

In general, a high quality packaging material is one that creates a goodoxygen and moisture barrier. Packaged goods are intended to last longertypically by reducing their interaction with oxygen and water, whichusually can deteriorate the product causing waste and other problems.Polymeric materials are often used as packaging materials because theycreate a good oxygen/moisture barrier and their appearance and shape canbe easily controlled. Plastic materials are also used in place of glassfor bottling because they are lighter, are more resistant to breakagewhen dropped, and can be less expensive. Several common polymericmaterials used for packaging as well as other uses are polyethylene(PE), polyethylene terephthalate (PET), polypropylene (PP),polycarbonate (PC), and polystyrene (PS).

Polystyrene is one of the largest volume thermoplastic resins incommercial production today. It is a hydrocarbon chain containing aphenyl group on every other carbon atom. Polystyrene is a durablepolymer that is frequently encountered in daily life. A few commonexamples of polystyrene are plastic toys, computer housings, foampackaging, foam cups, food storage containers, etc.

Polymer nanocomposites comprise polymeric materials and inorganiccompounds. When these inorganic components are properly incorporatedinto a polymer matrix, improvements in physical and mechanicalproperties can be displayed. The extent of uniformity of distribution ofthe inorganic compounds incorporated into the polymer matrix influencesthe characteristics of the nanocomposite.

Also, polystyrene is often times not suitable in certain environments.For example, polystyrene is typically not used in certain heatedenvironments, such as microwave ovens, and may succumb to heat generatedtherein. It would be desirable to obtain a polystyrene composition thatcan have higher heat stability and/or higher heat distortiontemperatures.

SUMMARY

An embodiment of the present invention is a nanocomposite comprising apolystyrene based polymer and a nanoparticle, which can be a treatednanoparticle formed by contacting a nanoparticle with an additive priorto combining with the monomer; wherein the nanoparticle is selected fromthe group consisting of silica, alumina, and combinations thereof.

In an embodiment, either by itself or in combinations with otherembodiments, the polystyrene based polymer and a treated or untreatednanoparticle are combined in a melt blend.

In an embodiment, either by itself or in combinations with otherembodiments, the polystyrene based polymer is formed by thepolymerization of at least one monomer and the treated nanoparticle arecombined with the at least one monomer prior to polymerization.

In an embodiment, either by itself or in combinations with otherembodiments, the additive comprises a silane moiety.

In an embodiment, either by itself or in combinations with otherembodiments, the additive is an alkoxy compound such as an alkoxy,dialkoxy, trialkoxy, etc., that can include methyl, ethyl, etc., thathas an R group attached, wherein the R group is chosen from the group analkane, an aromatic, and a vinyl group.

In an embodiment, either by itself or in combinations with otherembodiments, the additive is trimethoxysilane that has an R groupattached, wherein the R group is chosen from the group an alkane, anaromatic, and a vinyl group.

In an embodiment, either by itself or in combinations with otherembodiments, the additive is trimethoxysilane that becomes at least adimethyloxysilane having one methoxy reacted with an OH group tochemically bind the silane to the nanomaterial surface.

In an embodiment, either by itself or in combinations with otherembodiments, the additive comprises a moiety that is capable ofadsorbing volatile components from the polystyrene composite

In an embodiment, either by itself or in combinations with otherembodiments, the nanocomposite has a glass transition temperature of atleast 2° C. above the glass transition temperature of the polystyrenebased polymer without the treated nanoparticle.

In an embodiment, either by itself or in combinations with otherembodiments, the nanocomposite has a glass transition temperature of atleast 5° C. above the glass transition temperature of the polystyrenebased polymer without the treated nanoparticle.

In an embodiment, either by itself or in combinations with otherembodiments, the nanocomposite has a glass transition temperature of atleast 115° C.

In an embodiment, either by itself or in combinations with otherembodiments, the nanoparticle is present in an amount of from 0.001 wt %to 50 wt % of the nanocomposite.

In an embodiment, either by itself or in combinations with otherembodiments, the nanoparticle comprises nano sized crystals in a micronsized cluster morphology that at least partially disperses intonanoparticles during the melt blend with the polystyrene based polymerand treated nanoparticle.

In an embodiment, either by itself or in combinations with otherembodiments, the nanoparticle comprises nano sized crystals in a micronsized cluster morphology that at least partially disperses intonanoparticles during polymerization of at least one monomer.

An embodiment of the present invention includes an article produced fromthe nanocomposite.

An embodiment of the present invention is a method for production of apolymeric composite that includes combining a monomer with ananoparticle, or clusters made of nano crystals, to form a mixture andsubjecting the mixture to polymerization conditions to produce apolymeric composite. In an embodiment the nanoparticle is present in anamount of from 0.001 wt % to 50 wt % of the mixture.

In an embodiment, either by itself or in combinations with otherembodiments, the polymeric composite includes a styrenic polymer thatoptionally includes one or more copolymers or comonomers. The polymericcomposite can have an intercalated morphology, an exfoliated morphology,or both

In an embodiment, either by itself or in combinations with otherembodiments, the nanoparticle comprises silica or alumina. In anembodiment, either by itself or in combinations with other embodiments,the nanoparticle is a treated nanoparticle formed by contacting ananoparticle with an additive prior to combining with the monomer. In anembodiment, either by itself or in combinations with other embodiments,the additive comprises a silane moiety.

In an embodiment, either by itself or in combinations with otherembodiments, the additive is trimethoxysilane that becomes at least adimethyloxysilane having one methoxy reacted with an OH group tochemically bind the silane to the nanomaterial surface.

In an embodiment, either by itself or in combinations with otherembodiments, the additive is trimethoxysilane that has an R groupattached, wherein the R group is chosen from the group an alkane, anaromatic, and a vinyl group.

In an embodiment, either by itself or in combinations with otherembodiments, the nanoparticles increase the glass transition temperatureof the polymeric composite to temperatures of at least 2° C. above theglass transition temperature the polymeric composite without thenanoparticles, optionally at least 5° C. above the glass transitiontemperature the polymeric composite without the nanoparticles,optionally at least 10° C. above the glass transition temperature thepolymeric composite without the nanoparticles, optionally to at least115° C.

In an embodiment, either by itself or in combinations with otherembodiments, the nanoparticles increase the heat stability and/or Vicatof the polymeric composite.

An embodiment of the present invention includes an article produced fromthe polymeric composite.

The various embodiments of the present invention can be joined incombination with other embodiments of the invention and the listedembodiments herein are not meant to limit the invention. Allcombinations of various embodiments of the invention are enabled, evenif not given in a particular example herein.

DETAILED DESCRIPTION

Disclosed herein are polymer composites containing one or morenanoparticles and one or more polymeric materials and methods of makingand using the same. The polymer composite is a nanocomposite, and herein“nanocomposites” refer to materials that are created by introducingnanoparticles into a macroscopic material (e.g., polymeric material),which is commonly referred to as the matrix. According to theembodiments of the invention, the polymer composite comprises ananocomposite having nanoparticulates and a polymer matrix.

The incorporation of inorganic fillers, such as nanoparticles of silicaand/or alumina, may reduce polystyrene chain relaxation upon reheatingby constraining the flexible chains within the stiff inorganic layers.Thus, silica and/or alumina based nanocomposites may improve polystyreneby increasing the glass transition of the polystyrene or its dimensionalstability when subjected to higher temperatures. Also, the silica and/oralumina based nanocomposites may improve the microwavability of thepolystyrene. Also, the silica and/or alumina based nanocomposites mayimprove the dimensional stability of the polystyrene, such as with anincreased Vicat value or increase the heat stability of the polymericcomposite.

The nanoparticles may also include nanoparticulate material. As usedherein, the term “nanoparticulate” includes any particulate materialhaving a dimension of less than 250 ηm. The nanoparticulate material maybe selected from silica and/or alumina. The silica and/or alumina may bechosen from high purity silica and/or alumina, respectively. In anembodiment, the nanoparticulate material may include coarse silicaand/or alumina powders. In another embodiment, the nanoparticulatematerial may include high purity alumina such as DISPERAL®, DISPAL®,PURAL®, CATAPAL®, PURALOX®, CATALOX®, each commercially available fromSasol North America, Inc. In a further embodiment, the nanoparticulatematerial may include nanoparticulates of silica-alumina.

The nanoparticulate material may be selected from the group of silica,alumina, and silica-alumina and any other combinations thereof. In anembodiment, the nanoparticulates may have at least one dimension rangingfrom 1 to 250 ηm. In another embodiment, the nanoparticulates may haveat least one dimension ranging from 10 to 100 ηm.

In embodiments of the invention, the nanoparticle may be present in thenanocomposite in an amount ranging from 0.001 to 50 wt. % based on thetotal weight of the nanocomposite, alternatively from 0.5 to 25 wt. %,or from 1 to 10 wt. %.

In accordance with the invention, the nanocomposite comprises apolystyrene based polymer. The polymer may be present in thenanocomposite in an amount ranging from 50 to 99.9 wt. %, or from 90 to99.5 wt. %, or from 95 to 99 wt. % based on the total weight of thenanocomposite.

In an embodiment, the polystyrene based polymer can be formed frommonomers having a phenyl group. More specifically, the polymer can beformed from monomers having an aromatic moiety and an unsaturated alkylmoiety. Such monomers may include monovinylaromatic compounds such asstyrene as well as alkylated styrenes wherein the alkylated styrenes arealkylated in the nucleus or side-chain. Alphamethyl styrene,t-butylstyrene, p-methylstyrene, acrylic and methacrylic acids orsubstituted esters of acrylic or methacrylic acid, and vinyl toluene aresuitable monomers that may be useful in forming a polystyrene basedpolymer of the invention. These monomers are disclosed in U.S. Pat. No.7,179,873 to Reimers et al., which is incorporated by reference in itsentirety.

The polystyrene based polymer component in the nanocomposite can be astyrenic polymer (e.g., polystyrene), wherein the styrenic polymer maybe a homopolymer or may optionally comprise one or more comonomers.Styrene, also known as vinyl benzene, ethenylbenzene, phenethylene andphenylethene is an aromatic organic compound represented by the chemicalformula C₈H₈. Styrene is widely commercially available and as usedherein the term styrene includes a variety of substituted styrenes (e.g.alpha-methyl styrene), ring substituted styrenes such asp-methylstyrene, distributed styrenes such as p-t-butyl styrene as wellas unsubstituted styrenes.

In an embodiment, the styrenic polymer has a melt flow as determined inaccordance with ASTM D1238 of from 1.0 g/10 min to 100.0 g/10 min,alternatively from 1.5 g/10 min to 50.0 g/10 min, alternatively from 2.0g/10 min to 15.0 g/10 min; a density as determined in accordance withASTM D1505 of from 1.04 g/cc to 1.15 g/cm³³, alternatively from 1.05g/cm³ to 1.10 g/cc, alternatively from 1.05 g/cm³ to 1.07 g/cm³, a Vicatsoftening point as determined in accordance with ASTM D1525 of from 227°F. to 180° F., alternatively from 224° F. to 200° F., alternatively from220° F. to 200° F.; and a tensile strength as determined in accordancewith ASTM D638 of from 4000 psi to 7800 psi. Examples of styrenicpolymers suitable for use in this disclosure include without limitationPS525, PS529 and PS535, which are polystyrenes commercially availablefrom Total Petrochemicals USA, Inc

In some embodiments, the styrenic polymer or polystyrene based polymerfurther comprises a comonomer which when polymerized with styrenemonomer forms a styrenic copolymer. Examples of such copolymers mayinclude for example and without limitation α-methylstyrene; halogenatedstyrenes; alkylated styrenes; acrylonitrile; esters of methacrylic acidwith alcohols having 1 to 8 carbons; N-vinyl compounds such asvinylcarbazole and maleic anhydride; compounds which contain twopolymerizable double bonds such as for example and without limitationdivinylbenzene or butanediol diacrylate; or combinations thereof. Thecomonomer may be present in an amount effective to impart one or moreuser-desired properties to the composition. Such effective amounts maybe determined by one of ordinary skill in the art with the aid of thisdisclosure. For example, the comonomer may be present in a styrenemonomer containing reaction mixture to be polymerized in an amountranging from 0.1 to 99.9 wt. % by total weight of the reaction mixture,alternatively from 1 to 90 wt. %, and further alternatively from 1 to 50wt. %.

In an embodiment, the polymer or polystyrene based polymer alsocomprises a thermoplastic material. Herein a thermoplastic materialrefers to a plastic that melts to a liquid when heated and freezes toform a brittle and glassy state when cooled sufficiently. Examples ofthermoplastic materials include without limitation acrylonitrilebutadiene styrene, celluloid, cellulose acetate, ethylene vinyl acetate,ethylene vinyl alcohol, fluoroplastics, ionomers, polyacetal,polyacrylates, polyacrylonitrile, polyamide, polyamide-imide,polyaryletherketone, polybutadiene, polybutylene, polybutyleneterephthalate, polychlorotrifluoroethylene, polyethylene terephthalate,polycyclohexylene dimethylene terephthalate, polycarbonate,polyetherimide, polyethersulfone, polyethylenechlorinate, polyimide,polylactic acid, polymethylpentene, polyphenylene oxide, polyphenylenesulfide, polyphthalamide, polypropylene, polysulfone, polyvinylchloride, polyvinylidene chloride, and combinations thereof. Forexample, the thermoplastic material may be present in the nanocompositein an amount ranging from 0.1 to 50 wt. % by total weight of thenanocomposite.

In an embodiment, the polymer or polystyrene based polymer comprises anelastomeric phase that is embedded in a polymer matrix. For instance,the polymer may comprise a styrenic polymer having a conjugated dienemonomer as the elastomer. Examples of suitable conjugated diene monomersinclude without limitation 1,3-butadiene, 2-methyl-1,3-butadiene, and2-chloro-1,3-butadiene. Alternatively, the thermoplastic may comprise astyrenic polymer having an aliphatic conjugated diene monomer as theelastomer. Without limitation, examples of suitable aliphatic conjugateddiene monomers include C₄ to C₉ dienes such as butadiene monomers.Blends or copolymers of the diene monomers may also be used. Examples ofthermoplastic polymers include without limitation acrylonitrilebutadiene styrene (ABS), high impact polystyrene (HIPS), methylmethacrylate butadiene (MBS), and the like. The elastomer may be presentin an amount effective to impart one or more user-desired properties tothe composition. Such effective amounts may be determined by one ofordinary skill in the art with the aid of this disclosure. For example,the elastomer may be present in the styrenic polymer in an amountranging from 0.1 to 50 wt. % by total weight of the styrenic polymer, orfrom 1 to 25 wt. %, or from 1 to 10 wt. %.

In accordance with the invention, the nanocomposite also optionallycontains additives, as deemed necessary to impart desired physicalproperties. The additives used in the invention may be additives thatmodify silica and/or alumina. Additives suitable for use in theinvention include without limitation compounds containing silanemoieties. In an embodiment, the silane moieties may modify thenanoparticles by attaching to hydroxyl groups of the nanoparticles. Inan embodiment a trimethoxysilane having an R group on it, such as analkane, an aromatic, or a vinyl group, can become a dimethyloxysilanewith one methoxy reacted with an OH group to chemically bind the silaneto the nanomaterial surface.

The additives may contain compounds having silica and/or alumina thatare capable of adsorbing unreacted monomers or other volatilecomponents, such as dimers and trimers, in polystyrene. In anembodiment, the additives may contain compounds having moieties that arecapable of compatibalizing the nanoparticle with the matrix to reducethe release of unreacted monomers or other volatile components in thepolystyrene nanocomposite. In an embodiment at least a portion of anyunreacted monomers or other volatile components in the polystyrenenanocomposite are bound by adsorption to the silica and/or alumina. Inan embodiment the total volatiles are lowered to less than 200 ppm,optionally less than 100 ppm, optionally less than 50 ppm. In anembodiment the styrene monomer volatiles are lowered to less than 200ppm, optionally less than 100 ppm, optionally less than 50 ppm.

In an embodiment, the additives may contain moieties that can serve toincrease the surface area of the nanoparticles in order to increase theglass transition temperature of the polystyrene. In another embodiment,the additives may increase the surface area of the nanoparticles byamounts of at least 5%, optionally at least 10%. In another embodiment,the additives may increase the glass transition temperature of thepolystyrene to temperatures that can be used in microwave applications.In another embodiment, the additives may increase the glass transitiontemperature of the polystyrene to temperatures of at least 2° C. abovethe glass transition temperature the polymeric composite without thenanoparticles, optionally at least 5° C. above the glass transitiontemperature the polymeric composite without the nanoparticles,optionally at least 10° C. above the glass transition temperature thepolymeric composite without the nanoparticles, optionally to at least115° C.

These additives may be included in amounts effective to impart desiredphysical properties. In an embodiment, the additive(s) are added to thenanoparticles in amounts ranging from 0.001 to 50 wt. % based on thetotal weight of the nanoparticles. In another embodiment, theadditive(s) are included in amounts of from 0.01 to 40 wt. %. In anotherembodiment, the additive(s) are included in amounts of from 0.1 to 25wt. %. In another embodiment, the additive(s) are included in amounts offrom 0.1 to 10 wt. %. In another embodiment, the additive(s) areincluded in amounts of from 0.1 to 5 wt. %. In a further embodiment, theadditive(s) are included in amounts of from 1 to 3 wt. %.

In an embodiment, a method for production of the styrenic polymerincludes contacting styrene monomer and other components under properpolymerization reaction conditions. The polymerization process may beoperated under batch or continuous process conditions. In an embodiment,the polymerization reaction may be carried out using a continuousproduction process in a polymerization apparatus comprising a singlereactor or a plurality of reactors. In an embodiment of the invention,the polymeric composition can be prepared for an upflow reactor.Reactors and conditions for the production of a polymeric compositionare disclosed in U.S. Pat. No. 4,777,210, to Sosa et al., which isincorporated by reference in its entirety.

The operating conditions, including temperature ranges, can be selectedin order to be consistent with the operational characteristics of theequipment used in the polymerization process. In an embodiment,polymerization temperatures range from 88° C. to 238° C. (190° F. to460° F.). In another embodiment, polymerization temperatures range from93° C. to 182° C. (200° F. to 360° F.). In yet another embodiment, thepolymerization reaction may be carried out in a plurality of reactors,wherein each reactor is operated under an optimum temperature range. Forexample, the polymerization reaction may be carried out in a reactorsystem employing a first and second polymerization reactors that areeither both continuously stirred tank reactors (CSTR) or both plug-flowreactors. In an embodiment, a polymerization reactor for the productionof a styrenic copolymer of the type disclosed herein comprising aplurality of reactors wherein the first reactor (e.g., a CSTR), alsoknown as the prepolymerization reactor, operated in the temperaturerange of from 88° C. to 135° C. (190° F. to 275° F.) while the secondreactor (e.g., CSTR or plug flow) may be operated in the range of 93° C.to 165° C. (200° F. to 330° F.).

The polymerized product effluent may be referred to herein as theprepolymer. When the prepolymer reaches a desired conversion, it may bepassed through a heating device into a second reactor to achieve furtherpolymerization. The polymerized product effluent from the second reactormay be further processed as desired or needed. Upon completion of thepolymerization reaction, a styrenic polymer is recovered andsubsequently processed, for example devolatized, pelletized, etc.

In accordance with the invention, the nanoparticles may be incorporatedinto the polymer/monomer at any stage of the polymerization process, forexample, including without limitation before, during, or after thepolymerization process. In an embodiment, the nanoparticles areincorporated by mixing of a monomer with the nanoparticles. For example,by the mixing of styrene monomer with silica and/or alumina prior to insitu polymerization. In another embodiment, the nanoparticles areincorporated by compounding the polymerized product with thenanoparticles. For example, compounding polystyrene with silica and/oralumina. In yet another embodiment, the nanoparticles are incorporatedby solution mixing with a polymer, such as polystyrene, in a propersolvent, such as toluene or tetrahydrofuran. For example, solutionmixing polystyrene with silica and/or alumina in toluene.

In an embodiment, an article can be obtained by subjecting the polymericnanocomposite to a plastics shaping process such as foaming, sheetextrusion thermoforming, extrusion blow molding, extrusion coating, blowmolding, injection blow molding, injection stretch blow molding,thermoforming, and the like. The polymeric nanocomposite may be formedinto end use articles such as for example, packaging, office supplies,structural supports, laminate compositions, polymeric foam substrate,decorative surfaces, outdoor furniture, point-of-purchase signs anddisplays, house wares and consumer goods, building insulation, cosmeticspackaging, outdoor replacement materials, lids and food/beveragecontainers, appliances, utensils, electronic components, automotiveparts, enclosures, medical supplies, toys, piping, and the like.

Use of broader terms such as comprises, includes, having, etc. should beunderstood to provide support for narrower terms such as consisting of,consisting essentially of, comprised substantially of, etc.

The term “composite materials” refers to materials which are made fromtwo or more constituent materials (e.g., a layered compound and apolymeric material) with significantly different physical and/orchemical properties and which remain separate and distinct on amacroscopic level within the finished structure.

The term “dispersed” refers to the distribution of particles orparticulates and can refer to delamination of a layered materialresulting in the formation of disordered layers or sheets.

The term “nanocomposites” refers to materials that are created byintroducing nanoparticles, also termed filler materials into amacroscopic material (e.g., a polymeric material), which is typicallyreferred to as the matrix.

The term “nanoparticles” refers to particles having its largestdimension less than 100 nanometers (ηm).

The term “nanoparticulates” refers to particulates, including coarse orround particles, having a diameter of less than 250 nanometers (ηm).

Use of the term “optionally” with respect to any element of a claim isintended to mean that the subject element is required, or alternatively,is not required. Both alternatives are intended to be within the scopeof the claim. Use of broader terms such as comprises, includes, having,etc. should be understood to provide support for narrower terms such asconsisting of, consisting essentially of, comprised substantially of,etc.

The various aspects of the present invention can be joined incombination with other aspects of the invention and the listedembodiments herein are not meant to limit the invention. Allcombinations of various aspects of the invention are enabled, even ifnot given in a particular example herein.

While illustrative embodiments have been depicted and described,modifications thereof can be made by one skilled in the art withoutdeparting from the spirit and scope of the disclosure. Where numericalranges or limitations are expressly stated, such express ranges orlimitations should be understood to include iterative ranges orlimitations of like magnitude falling within the expressly stated rangesor limitations (e.g., from about 1 to about 10 includes, 2, 3, 4, etc.;greater than 0.10 includes 0.11, 0.12, 0.13, etc.).

Use of the term “optionally” with respect to any element of a claim isintended to mean that the subject element is required, or alternatively,is not required. Both alternatives are intended to be within the scopeof the claim. Use of broader terms such as comprises, includes, having,etc. should be understood to provide support for narrower terms such asconsisting of, consisting essentially of, comprised substantially of,etc.

Depending on the context, all references herein to the “invention” mayin some cases refer to certain specific embodiments only. In other casesit may refer to subject matter recited in one or more, but notnecessarily all, of the claims. While the foregoing is directed toembodiments, versions and examples of the present invention, which areincluded to enable a person of ordinary skill in the art to make and usethe inventions when the information in this patent is combined withavailable information and technology, the inventions are not limited toonly these particular embodiments, versions and examples. Also, it iswithin the scope of this disclosure that the aspects and embodimentsdisclosed herein are usable and combinable with every other embodimentand/or aspect disclosed herein, and consequently, this disclosure isenabling for any and all combinations of the embodiments and/or aspectsdisclosed herein. Other and further embodiments, versions and examplesof the invention may be devised without departing from the basic scopethereof and the scope thereof is determined by the claims that follow.

1-27. (canceled)
 28. A nanocomposite comprising: a polystyrene basedpolymer and a nanoparticle, wherein the nanoparticle comprises silica,alumina, or combinations thereof; and wherein the nanocomposite has anintercalated morphology, an exfoliated morphology, or combinationsthereof.
 29. The nanocomposite of claim 28, wherein the nanoparticle isan untreated nanoparticle.
 30. The nanocomposite of claim 28, whereinthe nanoparticle is dispersed within a polystyrene matrix of thenanocomposite and comprises delaminated layered particles orparticulates distributed within the polystyrene matrix.
 31. Thenanocomposite of claim 28, wherein: the nanoparticle is present in thenanocomposite in an amount ranging from 0.001 wt. % to 50 wt. % based ona total weight of the nanocomposite; and the polystyrene based polymeris present in the nanocomposite in an amount ranging from 50 wt. % to99.9 wt. % based on the total weight of the nanocomposite.
 32. Thenanocomposite of claim 28, wherein the nanoparticle comprisesnanoparticulate material having at least one dimension ranging from 1 to250 ηm.
 33. An article comprising the nanocomposite of claim
 28. 34. Ananocomposite comprising: a polystyrene based polymer and ananoparticle, wherein the nanoparticle comprises silica, alumina, orcombinations thereof; and a thermoplastic material in an amount rangingfrom 0.1 wt. % to 50 wt. %.
 35. The nanocomposite of claim 34, whereinthe nanoparticle is an untreated nanoparticle.
 36. The nanocomposite ofclaim 34, wherein the nanoparticle is dispersed within a polystyrenematrix of the nanocomposite and comprises delaminated layered particlesor particulates distributed within the polystyrene matrix.
 37. Thenanocomposite of claim 34, wherein: the nanoparticle is present in thenanocomposite in an amount ranging from 0.001 wt. % to 50 wt. % based ona total weight of the nanocomposite; and the polystyrene based polymeris present in the nanocomposite in an amount ranging from 50 wt. % to99.9 wt. % based on the total weight of the nanocomposite.
 38. Thenanocomposite of claim 34, wherein the nanoparticle comprisesnanoparticulate material having at least one dimension ranging from 1 to250 ηm.
 39. An article comprising the nanocomposite of claim
 34. 40. Ananocomposite comprising: a polystyrene based polymer and ananoparticle, wherein the nanoparticle comprises silica, alumina, orcombinations thereof; and a elastomeric phase in an amount ranging from0.1 wt. % to 50 wt. %.
 41. The nanocomposite of claim 40, wherein thenanoparticle is an untreated nanoparticle.
 42. The nanocomposite ofclaim 40, wherein the nanoparticle is dispersed within a polystyrenematrix of the nanocomposite and comprises delaminated layered particlesor particulates distributed within the polystyrene matrix.
 43. Thenanocomposite of claim 40, wherein: the nanoparticle is present in thenanocomposite in an amount ranging from 0.001 wt. % to 50 wt. % based ona total weight of the nanocomposite; and the polystyrene based polymeris present in the nanocomposite in an amount ranging from 50 wt. % to99.9 wt. % based on the total weight of the nanocomposite.
 44. Thenanocomposite of claim 40, wherein the nanoparticle comprisesnanoparticulate material having at least one dimension ranging from 1 to250 ηm.
 45. An article comprising the nanocomposite of claim 40.